The Vallejo Adult School is mourning the death of its principal Friday after he succumbed to injuries sustained in a hit-and-run incident last week.

Paul Jacobs, 63, was struck by an unidentified vehicle at about 10:40 p.m. Feb. 13 as he rode his bicycle in the bike lane on Columbus Parkway, near Hilary Way and not too far from his home off Ascot Parkway.

The driver failed to stop, and Jacobs was flown to John Muir Medical Center in Walnut Creek. He never regained consciousness again and died Thursday night, Superintendent Ramona Bishop said.

"He just never came back to us," Bishop said Friday as she prepared to notify the Vallejo City Unified School District staff.

The news stunned the tightly knit Vallejo Adult School campus.

"We knew it was serious -- very serious -- but we really just thought he'd pull through because Paul was such a fighter," said Dayle Kerstad, a retired Wardlaw Elementary School principal who has been leading the school in Jacobs' absence.

Kerstad, who helped transition Jacobs when he first took the job, had been getting the school ready for the principal's return, never considering he wouldn't make it.

"He will leave an incredible hole," said Kerstad, who gathered the school's staff Friday to break the news.

Still in the office were get well cards that the entire staff signed and planned to send to Jacobs on Friday.

"We'll still send them," Kerstad said, adding that his family might appreciate the gesture.

Jacobs came to the Vallejo Adult School in 2011, replacing longtime Principal Kay Hartley. He inherited a school with a dynamic and vocal population that had weathered years of budget cuts.

That school community rarely accepted decisions without a fight, and when Hartley announced her intention to leave, demanded to be included in the process to hire a new principal.

Out of that emerged Jacobs, who left a job at the state Department of Education and his home in Davis to move to Vallejo and head the school.

In past interviews with the Times-Herald, Jacobs would often say that the mere existence of the Vallejo Adult School proved how much the board and district valued it.

"They don't have to have an adult school," Jacobs said, noting that many districts had shut theirs down in the wake of the recession and budget cuts.

Under Jacobs, the school continued to offer programs important to the community as well as making sure credit recovery courses were available so high school students could graduate on time.

"He was just an innovator. He thought about things, and he wanted to implement them right away," Bishop said.

An avid bicyclist, Jacobs had routinely finished 100-mile rides in his younger days. He often noted how flat Davis was compared to the rolling hills of Vallejo.

It was not uncommon to see Jacobs at campus by 7 a.m. and not leave until after the last night classes concluded at about 10 p.m., Kerstad said. Jacobs also would routinely commute to and from school on his bicycle, making sure he was "lit up like a Christmas tree" for safety reasons, Kerstad said. When he was hit by the vehicle, Jacobs was wearing a helmet and his bike was equipped with lights and reflectors, police said.

Vallejo police are searching for the unidentified vehicle and driver that killed Jacobs. Based on pulverized glass debris found on the scene, investigators believe the vehicle has extensive damage to the windshield, and likely to the front bumper and hood.

Jacob's death is the third fatality from a hit-and-run since November.

Anyone with information about the incident can call Officer Shane Bower at (707) 649-3569 or Officer George Simpson at (707) 648-4014. Anonymous tips can be left at (800) 488-9383 or with the Solano Crime Stoppers, (707) 644-STOP (7867).

Jacobs is survived by his son, who flew from New York City to be at his father's bedside, and several sisters.

During the last week, students would often ask Kerstad about Jacobs' status, hopeful that he would soon return. Few students were on campus Friday, a traditionally lighter schedule for the Vallejo Adult School. The future leadership of the Adult School so far remains uncertain as staff and students grieve.

"He was obviously beloved by the kids and the staff," Kerstad said.

Jacobs was a product of public schools in Salinas and devoted his life to making a difference.

"What I find most important is, at the end of the day, I'm doing some meaningful work," Jacobs said, shortly after he began his last tenure.